CN87211754U

CN87211754U - Mechanical type load limiter

Info

Publication number: CN87211754U
Application number: CN 87211754
Authority: CN
Inventors: 黄国林
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-08-15
Filing date: 1987-08-15
Publication date: 1988-05-25

Abstract

The utility model relates to a mechanical type load limiter connected with a dragline on a hoisting machine in series. The utility model uses a spring as a component to bear lifting load, and the deformation displacement of the maximum lifting load is equal to the limit value of a limit switch; when the lifting capacity of the hoisting machine reaches the maximize designed value, the deformation displacement of the spring pushes the limit switch to cut off a lifting power supply and switch on an alarm, and accordingly the purpose that the load is limited is achieved.

Description

Mechanical type load limiter

The requirement that relevant rules according to national labour protection---" safety rules for lifting appliances " (GB6067-85) waits; various elevator machineries all should be equipped with load limitation device; to guarantee the safety of mechanical movement, avoid because the fatal crass's that the elevator machinery overload operation causes accident.That adopts at present often mostly is the strain-type load limitation device, on the pull bar of elevator machinery, paste strain-gauge, during the operation of (or sensor of other power) elevator machinery, pull bar stressed, by strain-gauge output, strain signal is exported lifting weight through multiple links such as electronic amplifier, analogue to digital conversion, decoding demonstrations.When strain output reached rated value, telltale was connected warning system simultaneously, and cut off the running power supply of elevator machinery, and elevator machinery quits work, thereby reaches the purpose of limit for tonnage.Passed through Jiangsu Province's provincial-level appraisal recently, and " the electric hoist overload protection tonnage digital display showing device " of batch manufacturing can be used as typical case's representative of this class device.Fig. 1 provides its structure and functional-block diagram.Obvious this apparatus structure more complicated, thereby manufacturing cost is also higher, because strain sensor is subjected to the influence of ambient temperature and humidity bigger, its functional reliability also is subjected to certain limitation simultaneously.Therefore, on some minor crane tools, applying of it just has certain difficulty unavoidably.

Task of the present utility model provides a kind of simple and reliable load limitation device for minor crane tool (as electric block) exactly.

Fig. 2 is the utility model---the work scheme drawing of mechanical type load limitation device, (6) they are the mechanical type load limitation device, and (7) are control box, and (8) are siren horn.It is connected on the drag-line of elevator machinery, and when mechanical movement, it bears the gravity of hoisting weight 1/2nd.

Fig. 3 is a structural representation of the present utility model.(1) is pull bar; (2) be limit switch; (3) be set screw; (4) be suspension ring; (5) belleville spring or other big rigid spring sheet.Stressed when suspension ring 4, i.e. during elevator machinery operation, belleville spring or other big rigid spring sheet 5 are out of shape by compression.According to calculating when can provide this elevator machinery design maximum and playing heavy lift, the deformation displacement value of spring, in limit switch 2, set spacing in advance again according to this shift value, when the deformation displacement of spring reaches design maximum and plays the corresponding deformation value of heavy lift, limit switch begins action, cut off and promote power supply, connect siren horn, thereby reach the effect of limit for tonnage.Set screw 3 is provided with for regulating spacing value.Owing to the utility model is that the minor crane tool designs, claimed structure is small and exquisite, and the rigidity of used spring wishes that appropriate value is arranged, so that make spacing value control within limits.Can not be too big, cause hoisting weight from the minimum value to the maxim, its corresponding deflection of spring displacement is little as can't to distinguish; Can not be too big, cause spacing value very big, the also corresponding heaviness that becomes of whole device.

The utility model is simple in structure, and reliable operation is cheap for manufacturing cost, though it can not show the weight of lifting by crane thing from the safety guard-safeguard angle, it meets the demands, and has played the effect of limit for tonnage protection.

Consider and reduce manufacturing cost as far as possible, for the minor crane tool, as the various elevator machineries in 0.5 ton to 6 tons the scope, can adopt belleville spring, deflection of spring displacement during the maximum hoisting weight, be within the spacing value may command face 2-3 millimeter of limit switch, part can be as Fig. 3 suitable configurations in addition for its structure.

Fig. 1 electric hoist overload protection tonnage digital display showing device functional-block diagram.

Fig. 2 mechanical type load limitation device work scheme drawing.

Fig. 3 mechanical type load limitation device structural representation.

Claims

1, a kind of load limitation device of elevator machinery is made up of institutes such as the impression part that plays heavy lift, Circuits System, annunciators, it is characterized in that having formed heavy lift with belleville spring or other big rigid spring sheet experiences part, one end of belleville spring or other big rigid spring sheet links to each other with housing, the other end links to each other with pull bar (1), and pull bar (1) termination contacts with limit switch (2).